Sectional ore-bearing water-carrying mining and mining method in Pangushan tungsten mine

This mining method was adopted at the 63218 stope of No. 91 vein of the northern group of the Pangushan tungsten mine. The veins are about 600m long, with an average thickness of 0.19m, an inclination of 42° to 55°, and an average grade of 2.843%. The top and bottom plates are quartz sandstone and sandy shale , and the joints are relatively developed and moderately stable. The shape of the veins did not change much, but the changes in the occurrence of the veins were large, and there were more branches and alternations.
The stage height is 65m. The length of the nugget is controlled by two ends of the fault and is 68m long. Due to the slow dip angle of the vein, the ore can not be completely slid out, and the mine is inclined up to 90m, so it is divided into three sections. The height of the top and bottom columns of the nuggets is 3m. The segmented bottom column is 2.5m high. The structure of the nugget is shown in Figure 1.

Fig.1 The section of the Baogushan tungsten mine
1-stage transportation roadway; 2- return airway roadway; 3-section roadway;
4-shun patio; 5-stage bottom column; 6-segment bottom column
There is no digging patio in the stope. For the pedestrians and the installation of the hydraulic transport system, three east and west courtyards are set up. The middle pass patio is erected considering the range of the water gun and reducing the exposed surface of the upper plate. The size of the paradise patio is 2 x 1.5m, wood support. In the bottom column of the stage, the wooden leakage is used for ore mining, and the funnel spacing is 5m.
Due to the segmentation of the ore, each section requires a cutting project.
When the sub-section is taken to the design elevation, the working face and the retained ore are leveled, and then the surrounding rock is expanded to a size of 1.8×1.2m. The funnel digs in every 5m along the section roadway. Both the bottom and the recovery were broken. The horizontal width of the width is 1.69m.
In the stope, except for the pillars on the Shun Road, the rest are not supported, but due to the development of the joints near the courtyard of Xishun Road, there is a 3×3m pillar.
The ore collected is relatively uniform. Some ore can be released from the sea, and some ore, especially fine ore, must be transported by water.
Since the stope does not have a patio in the upper stage, the natural pressure head cannot be used to supply water from the upper stage. To ensure the working pressure of the water gun, a hydraulic system in which the water pump is directly supplied is used. The water supply system consists of two 25m 3 water supply tanks, a pressurized pump and its associated piping. The pump is 80DL30×3 type, with a head of 90m, a flow rate of 43m 3 /h, and a motor power of 17kw. It is installed in the central smooth road patio. The main water supply pipe is made of ф75mm steel pipe and connected to the nozzle through a ф50mm hose. The jet is produced by a nozzle. The nozzle is conical, the taper angle is 5°55′, and it is manufactured by mining. The outlet diameter is ф13mm.
The advantage of this mining method is that it has strong adaptability and is easy to recover the veins with inclination and inclination change, and the recovery rate is high. The disadvantage is that the amount of cutting work is large; there are many bottom columns and it is difficult to recycle.

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12 Layer PCB



12 layer PCB stackup and thickness


12 Layer PCB Stack Up

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12 layer PCB stackup thickness


12 Layer PCB




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